Amazon.com: AVIMABASICS Harmony One Battery Replacement Part Compatible with Logitech Harmony One, 720, 850, 880, 885, 890 Pro, H880 Advanced Universal Remotes - Parts: 190304-0000 (950mAh 3.7V Li-ion) : Electronics
Amazon.com: Youejoeq (2-Pack) logitech r-ig7 Battery Replacement for logitech Harmony one 900 850 880 885 890 Pro H880,fit Part no R-IG7 190304-0000 f12440023 : Electronics
Battery for Logitech Harmony One 720 780 785 880 885 890 895 900 R-IG7 — Battery Mate
Replacement Battery for Logitech Harmony One, 900, 720, 850, 880, 885, 900 PRo | eBay